tion of validator names to consider to be "weak".
            If there are two errors at the same level of the instance
            and one is in the set of weak validator names, the other
            error will take priority. By default, :validator:`anyOf` and
            :validator:`oneOf` are considered weak validators and will
            be superseded by other same-level validation errors.

        strong (set):
            a collection of validator names to consider to be "strong"
    c